Field of Invention
The present invention relates to a textile technical filed, and more particularly to a ring composite spinning method based on film filamentization.
Description of Related Arts
The textile fibers can be divided into natural fibers and chemical fibers by source; and the chemical fibers generally include regenerated fibers and synthetic fibers. Because the natural macromolecules already existing in the natural world fail to meet the requirements of the textile processing due to the features such as the length and thickness of the macroscopic aggregation morphology, the natural macromolecules need to be re-aggregated into a fibrous form through a chemical method to meet the textile processing requirements and form the regenerated fibers, such as the regenerated cellulose fibers and various viscose fibers. The synthetic fibers are formed with raw materials of petrochemical micromolecules successively through steps of: chemically synthesizing the micromolecules into macromolecules; and processing into chemical filaments through a spinning process. According to the performance of the macromolecular materials, the production of the chemical filaments can be divided into melting spinning and solution spinning. The melting spinning is applicable to the macromolecular materials having the obvious hot melting point and the melting temperature lower than the decomposition temperature, and the process thereof comprises steps of: preparing a spinning melt (including melt slicing, melt drying, etc.); feeding the spinning melt into a twin-screw extrusion high-temperature melt spinning machine, and heating the spinning melt into hot melt liquid; extruding the hot melt liquid from the spinneret orifices; processing the melt stream with stretching and solidification; conditioning and oiling; and winding. The as-spun filaments formed through winding are generally the multi-filaments containing at least hundreds of mono-filaments, which cannot be directly applied in the textile processing and generally need to be further processed with dividing, secondary hot drafting and forming, post-processing such as false twisting or air texturing, and winding. After the post-processing, the linear assembled as-spun filaments with cylindrical cross-section shape can be used for a variety of composite spinning. It can be seen that: the filaments processed with the melt spinning require a complex process to be applied in the texture fiber processing with the long process flow and the low production efficiency. The solution spinning is applicable to the macromolecular materials without the obvious hot melting point, or with the melting temperature higher than the decomposition temperature. The solution spinning process comprises steps of: dissolving the polymers in the spinning solution prepared with an appropriate solvent; filtering, defoaming and mixing, and thereafter placing the spinning solution in the solution tank of the solution spinning machine; under the high-pressure push effect, pressing the spinning solution out of the spinneret orifices and into the coagulation bath to be coagulated into the as-spun filament fibers (wherein the coagulation can be divided into the wet method and the dry method according to the different coagulation baths), and obtaining the as-spun filaments; processing the as-spun filaments with stretching and solidifying; washing the as-spun filaments to remove the attached coagulation bath liquid and solvent; conditioning and oiling; and winding. The as-spun filaments formed through winding are generally the multi-filaments containing at least hundreds of mono-filaments, which cannot be directly applied in the textile processing and generally need to be further processed with dividing, secondary hot drafting and forming, post-processing such as false twisting or air texturing, and winding. The cross-section of the filament is adjustable according to the shape of the spinneret orifices for forming the as-spun filament fibers of various shapes. After the post-processing, the linear assembled as-spun filaments with cylindrical cross-section shape can be used for a variety of composite spinning. It can be seen that: the filaments processed with the solution spinning require a complex process to be applied in the texture fiber processing with the long process flow and the low production efficiency. Therefore, conventional filament fiber formation generally employs spinneret orifices to perform linear extruding fiber forming, which requires long process flow and complex equipment.
With the technology development of the textile materials and the higher and higher demands of the people on the clothing materials and styles, the requirements on the spinning technology is higher and higher. Various spinning methods emerge in endlessly, such as the sirofil spinning, the siro spinning, the compact spinning, the cable spinning, the core spinning and the embedded spinning. The above spinning methods greatly enrich the spinning processing means, and obviously increase the quality of the resultant spun yarn. The spinning methods, such as the sirofil spinning, the embedded spinning and the core spinning, relate to the staple fibers and the filament fibers, belonging to the category of ring filament composite spinning. The sirofil spinning is to feed one filament and one roving strand with a certain spacing, so that the filament and the staple fiber strand are twisted with each other to form a sirofil spun yarn. The core spinning is to feed one filament from the center of one or two roving strands, so as to realize the composite yarn structure with the staple fibers as the sheath and the filaments as the core. The embedded spinning is to feed two filaments with a certain spacing into the front roller nip and then feed two strands with a certain spacing symmetrically into the front roller nip, so that one filament and the strand at the same side are twisted with each other to form a pre-twisted composite strand and afterwards join with the other pre-twisted composite strand to conduct a convergence twisting, so as to form an embedded composite yarn with a complex structure. However, the above composite spinning method requires that the positions of the filaments and the staple fiber strands are fixed and invariant relatively, so that the positions of the filaments are fixed with respect to the positions of the staple fibers in the obtained composite yarn structure, resulting in that the filaments cannot perform abundant migrations within the composite yarn body maximumly, so that the filaments cannot mix and cohere with the staple fibers within the yarn body naturally and uniformly. Moreover, the used multi-filaments are well formed after industrialized stretching, shaping and winding and are in a package form, wherein the multi-filaments are aggregated into a linear shape like a cylinder and the mono-filaments in the multi-filaments fail to effectively disperse into the staple fiber strands. Thus, all the composite yarn produced with the above composite spinning methods has the problems that the cohesion force between the filaments and the staple fibers is not enough and the relative sliding between the filaments and the staple fibers in the subsequent processing easily occurs, leading to the low spinning efficiency and the poor cloth cover quality and fabric abrasive resistance. In order to solve the problem of the relatively poor cohesion force between the filaments and the staple fibers in the composite spinning, the Chinese patent publication of CN100523340C, published on Aug. 5, 2009, “Filament composite yarn and production method thereof grey cloth and fabric with filament composite yarn, and fiber opening device for composite spinning”, disclosed a production method of the long-short composite yarn in the ring spinning machine. The production method is to process the synthetic fiber multifilament with electrical fiber opening, so as to enable the multi-filaments to enter the front roller nip for being processed together with the staple fiber strands via the composite spinning twisting. Each mono-filament in the multi-filaments is fiber-opened into a hashed fibrous shape, which is able to greatly increase the distribution of each mono-filament in the composite yarn section and enhance the cohesion force between the filaments and the staple fibers. However, the above method adopts the electrical fiber opening, which has the high cost, has the potential danger of fire due to the electrostatic spark in the production process, and thus does not have the practical application and generalization performance in the factory. Moreover, the method directly adopts the package form with good forming after industrialized stretching, shaping and winding, without shortening the entire industrial chain and flow of the composite yarn production using the filaments and the staple fibers.
The above is the problems existing in the conventional filament fiber forming method, process and performance as well as the problems in the composite yarn spinning with chemical filaments and the common staple fibers. With the continuous development of the fibrous materials in the application technology of various fields, the nanofiber material has become the hot issue in the research and the function application. The nanofiber material has a diameter in a range of 1-100 nm and has the performance advantages such as the high porosity, high specific surface area, high length-diameter ratio, high surface energy and high activity, reflecting the excellent strengthening, anti-bacteria, water-repellency and filtering functions. The nanofiber material can be applied in various fields such as separation and filtering, biomedical treatment, energy material, polymer reinforcement and photoelectric sensing. With the extension and requirements of the application fields of the nanofibers, the forming and preparation technology of the nanofibers have been further developed and innovated. So far, the preparation methods of the nanofibers mainly comprise the chemical method, the phase separation method, the self-assembly method and the spinning processing method. The spinning processing method is considered as the most promising method potential in the large-scale preparation of the polymer nanofibers, including the electrostatic spinning method, the two-component composite spinning method, the melt-blowing method and the laser stretching method. The laser ultrasonic stretching method utilizes the laser radiation to heat the fibers and meanwhile processes the fibers with stretching under the ultrasonic condition, generating the stretching ratio of 105 times for preparing the nanofiber strands, which is a method of post-processing common filaments. In addition, the other nano spinning methods are all directly related to the spinneret orifice with a common point that the fiber diameter reaches a nanoscale with the synergistic effect of spraying and stretching. The Chinese patent application of ZL201611005678.4, published on Nov. 11, 2016, “Multi-responsive controllable filtration electrostatic-spinning nanofiber film and preparation method thereof”, disclosed a method comprising steps of: placing a thermo-sensitive pH-responsive polymer solution into an electrostatic spinning machine; and after being processed with spraying and laying in the electrostatic spinning machine, forming the nanofiber film. The key problem of the electrostatic spinning is that: the electrostatic spinning belongs to the spinning with negative stretching under no nipping. The electrostatic spray stream forms the Taylor cone during the filamentization process, and the spray stream for fibers is processed with insufficient drafting, which causes that: the macromolecules in the nanofibers have poor orientations; the nanofibers are required to be further attenuated; the strength is low and the size scale is required to be further decreased. Moreover, the filamentization process of the Taylor cone form causes that the fibers obtained through the electrostatic spinning are unable to be laid orderly and longitudinally, so that the spun fibers are difficult to be processed with linear collecting and gathering for being mainly applied in the production of the nanofiber film material. The Chinese patent application of ZL201610753443.7, published on Aug. 29, 2016, “Coaxial centrifugal spinning device and method”, disclosed a centrifugal spinning method through arranging multiple layers of needles internally and externally on the coaxial centrifugal tube, so as to realize the high-speed rotation coaxial centrifugal tube for the scale production of the superfine fibers, and even realize the centrifugal spinning method of the nanofibers. The Chinese patent application of ZL201611154055.3, published on Dec. 14, 2016, “Titanium dioxide/polyvinylidene fluoride microfiber/nanofiber film and centrifugal spinning preparation method thereof”, disclosed a method comprising steps of: mixing self-prepared anatase-type TiO2 and polyvinylidene fluoride (PVDF), and preparing the centrifugal spinning solution; processing with centrifugal spinning on the centrifugal spinning machine; and forming the micro-nano fibrous film. The key problem of the centrifugal spinning is that: through spraying under the high-speed rotation centrifugal effect, the filaments formed through the spray stream are laid circularly, so that the spun fibers are difficult to be arranged orderly and longitudinally and collected and gathered linearly for being mainly applied in the production of the nanofiber film material. During the spinning process, the centrifugal spinning also belongs to the spinning with negative stretching under no nipping. The drafting force of the centrifugal spray stream is limited by factors such as the rotation speed and the air resistance, causing the insufficient drafting of spinning. The insufficient drafting causes that: the macromolecules in the nanofibers have the poor orientation degree; the nanofibers are required to be further attenuated; the strength is low and the size scale is required to be further decreased. However, the small diameter of the nanofibers leads to the low strength and abrasiveness of the nanofibers, so that the nanofibers easily abrade and fall off if being coated on the fabric surface and therefore the coated textile product has the poor functional durability, causing that the nanofibers can be lapped merely with a small amount to be processed into the nanofiber film and are unable to be processed with the conventional drafting and twisting for forming the yarn, which seriously limits the industrialized application of the nanofibers. If converting the nanofibers into macroscopic linear mass, the products such as the medical and functional clothing and the industrial fabrics of various types can be produced with the modern spinning means, which will break through the performance and value of the traditional textile products and has the wide application prospect. Thus, the insufficient drafting in the nano spinning production causes that: the macromolecules of the nano-spun fibers have poor orientations to weaken nanofibers; the nano-spun fibers are insufficiently attenuated due to poor drafting. The weakness of the nanofibers causes the poor abrasiveness and durability, so that the nanofibers easily abrade and fall off if being coated on the fabric surface and are unable to be processed by the conventional ring spinning, resulting in merely a small amount of the nanofibers applied in textile industrial production as non-woven fabrics or the nano films without large applications in common high speed textile processing.
In recent years, the production of the high-functionality high-quality yarn and fabric has been paid more and more attentions in the textile field. How to assign the high-functionality and the high-quality to the traditional textile yarn becomes the hot issue in the conventional textile processing. Since the nanofibers have many high-functionality and high-quality properties, if the nanofibers can be processed into the macroscopic yarn, the production problem of the scale high-speed textile processing of the nanofiber yarn can be solved and the products such as the medical and functional clothing and the industrial fabric of various types can be produced by the conventional spinning frames, which will break through the performance and value of the traditional textile products and has the wide application prospect. Currently, the processing of nano materials into the yarn is mainly reflected in trying the pure nano yarn processing technology. The Chinese patent application of ZL201310153933.X, published on Nov. 9, 2005, “Production and application of nanofiber yarn, band and plate”, disclosed a method comprising steps of: adopting a banded or plate-shaped carbon nanotube array which is arranged in parallel; processing with drafting and twisting, and forming the nanofiber yarn. The obtained nanofiber band or yarn can be applied in fields of composite reinforcement organic polymer, electrode manufacturing, optical sensors and so on. The Chinese patent application of ZL201310454345.X, published on Sep. 27, 2013, “Oriented nanofiber yarn continuous preparation device and method”, disclosed a method of directly processing the fibers prepared by the nanofiber spinning with twisting and winding for forming the linear material with the self-made rotation twisting device. However, the nanofibers have the thin shape dimension and the weak strength, and especially the carbon nanofibers have the feature of the high brittleness, causing that the fibers will be seriously damaged and destroyed after twisting the pure nanofibers into the yarn. According to the report, when twisting the nanofibers into the yarn, the nanofibers have many torsional fractures, so that the nanofibers cannot play the mechanical advantages, resulting in that the effect of the spun yarn is far lower than the expected theoretical effect. Based on the technical problems and bottlenecks of the pure nanofiber yarn, the Chinese patent application of ZL201210433332.X, published on Nov. 1, 2012, “Spinning device and spinning method for composite yarn of nanofibers and filaments”, disclosed a method comprising steps of: introducing the filaments into two nanofiber receiving disks during electrostatic spinning, so that the nanofibers are adhered to the two filaments; then processing the two filaments covered with nanofibers by twisting and combining, and obtaining the filament/nanofiber composite yarn with the ultrahigh specific surface area of the nanofibers and the high strength characteristic of the filaments. Although the above application solves the difficult problem that the pure nanofibers are difficult to be spun into the yarn due to the weak strength, the above application merely involves processing the filaments and the nanofibers by twisting into the yarn, which just concerns very small-scale textile applications, as the conventional large-scale textile processing involves the natural chemical staple fiber spinning. Thus, the above application has the narrow processing application range, and fails to solve and realize the nano composite spinning production of the conventional staple fibers in the textile industrial field. Based on the above technical problems and bottlenecks, especially the technical production demands of the composite yarn made of the nanofibers and the conventional cotton fibers, the Chinese patent application of ZL201310586642.X, published on Nov. 20, 2013, “Preparation method of composite yarn blended with nanofibers”, disclosed a method comprising steps of: during a carding process, directly spraying nanofibers into the output cotton web of the carding machine with the electrostatic nano spinning, and mixing with the cotton web to form the cotton/nanofiber sliver; then processing the cotton/nanofiber sliver into a roving for spinning to get a blended composite yarn. The above method seems to be easy, and effectively combines the nanofibers with the cotton fibers. However, the method has the problems of the inherent principles and practical production, and the key problem is that the nanofibers have the large specific surface area and have the strong adhesion and cohesion force with the conventional cotton fibers. In this case, during the drafting process of roving and spinning, the cotton fibers are difficult to freely and smoothly slide relative to each other, easily causing the problems of hooks, drafting difficulties and uneven drafting, finally resulting in that the yarn spun with twisting has the poor quality and fails to realize the production and processing of the high-functionality high-quality nanofiber composite yarn. The Chinese patent application of ZL201110221637.X, published on Aug. 4, 2011, “Method and system for preparing nanofiber coating on surface of yarn or fiber bundle”, disclosed a method that: when the yarn passes between the spout of the spinning nozzle and the collector, the yarn surface is directly under the spraying effect of nanofiber spinning of the nozzle, and therefore a layer of nanofiber coating film is formed on the surface. Obviously, the above application belongs to the spraying method. The nanofibers fail to enter the yarn body and generate the good cohesion effect with the staple fibers inside the yarn, inevitably resulting in that the nanofiber coating layer separates from the yarn surface or falls off due to the abrasion in the subsequent use and processing, causing poor durability of the product. Through analyzing the above technologies, it can be known that: the insufficient drafting during the nanofiber production incurs poor orientations of macromolecules in the nanofibers to weaken nanofibers, and insufficient thickness attenuation, which causes the poor abrasiveness and durability, so that the nanofibers easily abrade and fall off if being coated on the fabric surface and are hard to be processed by the conventional ring spinning; if adopting the composite spinning with the conventional fibers through the electrostatic nano-spinning or the centrifugal spinning, the uniform mixing will cause the uneven and bad composite drafting and the difficulty of high-qualified yarn formation, the simple surface spraying coating cannot realize even distribution and effective cohesion of the composite nano-fibers and conventional micro-fibers, and the nanofibers easily abrade and fall off. Thus, the contradictory difficult problems of the composite yarn formation by combining nanofiber spinning and the conventional fiber spinning cause that: merely a small amount of the nanofibers can be processed into the non-woven fabric or the nano film in the textile industrial production and the nanofibers are still unable to be applied in the scale high-speed textile yarn processing production, which seriously limits the textile industrialized application of the nanofibers.
Different from the spinning process, the film forming process is to convert polymer materials into a sheet form and then wind into a roll. There are various processing methods for forming the plastic film, such as the rolling method, the casting method, the blow molding method and the stretching method. According to above methods, the plastic film production employs an external force to orientate and arrange the polymer inner chain or crystal in parallel to the film surface within an appropriate temperature range (high-elastic state) of above the glass transition temperature and below the melting point; then a film-like profile is formed. Subsequently, heat-setting is adopted for the tensioned film profile to fix the oriented macromolecular structure which is then cooled, pulled, and winded. During the process of film blow molding, according to different extrusion and traction directions, it can be divided into three types: flat blowing, up blowing and down blowing. There are also special blow molding methods such as up extruding up blowing. Film material has many special features: 1) the most basic performance of the film material is a flat appearance with clean surface and no dust or oil; 2) the thickness and length of the standard specifications are controllable, wherein the thickness can be as low as nanoscale, and the width can be precisely controlled at the macro millimeter scale, effectively ensuring the mechanical strength of the fiber film and precise stabilization of film shape size, so that the specifications of each film material deviations are in line with customer requirements; 3) for the transmittance and gloss according to customer requirements for different production, high transmittance may be maintained according to transmittance requirement, but the gloss must be maintained for bright and beautiful effects; 4) tensile strength, elongation at break, tearing strength, impact strength and so on are easy to achieve compliance; 5) according to use, application and performance, the processed film can have various shape sizes, different specifications of the meshes, cracks, etc., giving the film material excellent moisture permeability and air permeability; 6) size and chemical stability, as well as surface tension are easy to reach high standards. The widely used film materials have many types, such as polymer film material, aluminum film material, microporous film material, which are mainly used in the packaging of food, medicine and cosmetic products, the filter purification of air and water, the filtration of virus and dust, and so on. It can be seen that the conventional film is basically not used for the production of textile yarn and fabric, wherein the key issue is: the relatively stable film is difficult to be freely migrated and hugged together; therefore direct twisting of the film material cannot get the migration and coherence structure of conventional filaments and staple fiber spun yarns by twisting, leading to appearance and feel performance of the film spun yarn are quite different from that of conventional filaments and staple fiber spun yarns.